Bone is a composite material that contains impure hydroxyapatite, collagen and a variety of non-collagenous proteins, as well as embedded and adherent cells. Due to disease, a congenital defect or an accident, a person may lose or be missing part or all of one or more bones or regions of cartilage in his or her body, and/or have improper growth or formation of bone and/or cartilage.
That an organism is missing part of a bone or has a defect is not necessarily a permanent condition, and there are known means by which to address some of these conditions. For example, mammalian bone tissue is known to contain one or more proteinaceous materials that are active during growth and natural bone healing. These materials can induce a developmental cascade of cellular events that results in bone formation. Typically, the developmental cascade of bone formation involves chemotaxis of mesenchymal cells, proliferation of progenitor cells, differentiation of cartilage, vascular invasion, bone formation, remodeling and marrow differentiation. Thus, the control or use of this already existing system can be advantageous when seeking to regenerate or to repair bone.
In order to facilitate regrowth of bone, it can be advantageous to include or to co-administer stem cells. Stem cells may, for example, be introduced when inserting an implant. Unfortunately, the full potential of stem cells to regenerate tissue or bone has not been reached. The present invention is directed toward increasing the efficacy of stem cell applications.